Guwahati: Researchers at the Indian Institute of Technology Guwahati (IIT Guwahati) have achieved a significant breakthrough in the field of speech technology with the development and patenting of ‘LOQU,’ a device to generate human speech signals directly from vocal cord vibration signals.
LOQU has been created by a team of researchers led by Dr LN Sharma under the guidance of Prof Samarendra Dandapat of IIT Guwahati’s Department of Electronics and Electrical Engineering.
Derived from the Latin word for “To speak or talk,” this technology captures vocal fold movement without invasive procedures, utilising sensors placed over the throat. This innovative approach allows for the reconstruction of speech signals from vocal cord vibrations, offering promising applications for speech-impaired individuals and medical settings.
Speech production begins with airflow from the lungs through the windpipe, facilitated by the larynx or voice box, which acts as a conduit between the throat and windpipe. Inside the larynx are the vocal cords or vocal folds, regulated by the glottis, controlling airflow between the lungs and mouth. The voice box adjusts the space between vocal folds to create sounds, which travel through the vocal tract, modulating in volume and pitch to form a voice.
During speech, vocal folds vibrate due to intrinsic laryngeal muscle movement. In some cases, like mutism (an inability or unwillingness to speak, resulting in the absence or marked paucity of verbal output) from apraxia (a disorder of the brain and nervous system in which a person is unable to perform tasks or movements when asked, even though, the request or command is understood but they are willing to perform the task), individuals may have normal vocal fold vibration without sound production due to coordination issues in tongue or throat muscles essential for speech.
Speaking about the device, Prof Dandapat said, “This breakthrough holds immense promise for individuals facing speech impairments, offering a viable solution with clear and comparable speech signals, as demonstrated in comparison tests. With LOQU, we aim to empower those in need and drive impactful innovations in the medical and communication domains.”
Explaining the research, Dr Sharma said that the method involves capturing vocal fold vibrations using non-invasive sensors and processing these signals electronically to generate speech harmonics. “The resulting speech signals closely resemble traditional speech, as validated through comparison tests with signals recorded using conventional microphones,” he added.
The reconstructed speech signals have been found to be clear and comparable to traditional speech in extensive comparison tests. These results hold significant potential for individuals struggling with speech impairments, offering a viable alternative to traditional microphones and enhancing speech clarity. The prototype of LOQU has been developed on a laboratory scale at a cost less than Rs 2000.
The patented technology represents a significant milestone in speech research and innovation, with ongoing clinical testing aimed at further validating its effectiveness and exploring diverse applications in medical and communication fields.